Known solutions for forming an immersion agent film are mostly based on the approach of providing the objective with a sealing collar which is filled with immersion agent by means of a permanent feed, and optionally is also emptied by means of the same. The design of the collar enables, on the one hand, the formation of the immersion, and on the other hand prevents the immersion agent from flowing off into the device. Such solutions are described, by way of example, in WO 2008/028475 A2/A3, US 2010/0027109 A1, DE 101 23 027 B4, and DE102005040828.
In one variant according to DE 101 23 027 B4, the medium is introduced by means of a cannula directly adjacent to the front lens of the microscope.